Security advisory

{
  "id": "b3bfc700397df76f36fd3d9a10b6dc834a0374b95e78531b010504be3a2a343c",
  "url": "https://osv.dev/vulnerability/CVE-2019-9901",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2019-9901",
    "summary": "Envoy 1.9.0 and before does not normalize HTTP URL paths. A remote attacker may craft a relative path, e.g., something/../admin, to bypass access control, e.g., a block on /admin. A backend server could then interpret the non-normalized path and provide an attacker access beyond the scope provided for by the access control policy.",
    "evidence": "osv:CVE-2019-9901",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2019-9901",
      "aliases": [
        "CVE-2019-9901",
        "GHSA-2wmf-p7f8-w42h",
        "GHSA-xcx5-93pw-jw2w"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/envoyproxy/envoy",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "37bfd8ac347955661af695a417492655b21939dc"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "1.9.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.9.0",
            "v1.8.0",
            "v1.7.0",
            "v1.6.0",
            "v1.5.0",
            "v1.4.0",
            "v1.3.0",
            "v1.2.0",
            "v1.1.0",
            "v1.0.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2019-9901.json"
          }
        }
      ],
      "modified": "2026-10-20T10:52:46.352146602Z",
      "provider": "osv",
      "references": [
        "https://groups.google.com/forum/#%21topic/envoy-announce/VoHfnDqZiAM",
        "https://github.com/envoyproxy/envoy/security/advisories/GHSA-xcx5-93pw-jw2w",
        "https://www.envoyproxy.io/docs/envoy/v1.9.1/intro/version_history",
        "https://github.com/envoyproxy/envoy/issues/6435"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2019-9901",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 383809,
  "published_at": "2019-04-25T16:29:01.2+00:00"
}